The Geometric Distribution
Geometric distribution - A discrete random variable X is said to have a geometric distribution if it has a probability density function (p.d.f.) of the form:
-
P(X = x) = q(x-1)p, where q = 1 - p
If X has a geometric distribution with parameter p, we write X ~ Geo(p)
Expectation and Variance
If X ~ Geo(p), then:
-
E(X) = 1/p
-
Var(X) = q/p2, where q = 1 – p
